Internal mold release agents and use thereof in the production of molded products

ABSTRACT

The present invention is directed to a novel internal release agent for the production of polyurethane and/or polyurea elastomers, to an isocyanate reactive composition containing that release agent and to the use of the release agent in a RIM process. The release agent is the reaction product of i) a polyester derived from a polymerized fatty acid and either neopentyl glycol or 2,2,4-trimethyl-1,3-pentane diol and ii) an aliphatic monoisocyanate.

BACKGROUND OF THE INVENTION

Internal mold release agents used in the production of moldedpolyurethane and polyurea products are known. U.S. Pat. Nos. 4,201,847and 4,254,228 describe an internal mold release which is the reactionproduct of an organic polyisocyanate and an active hydrogen containingfatty acid ester.

U.S. Pat. No. 3,925,527 describes an internal mold release which is thereaction product of a fatty acid ester and an organic monoisocyanate.

While these types of internal release agents have met with some success,neither is totally satisfactory for many applications. One shortcomingof all internal release agents to date, including those described above,is the inability to release from a bare metal mold, such as steel oraluminum.

DESCRIPTION OF THE INVENTION

The present invention is directed to a novel internal mold release agentcomprising the reaction product of

a) a polyester (i) having an OH number of from about 50 to about 550,preferably from about 50 to about 300, and most preferably from about100 to about 200, (ii) having an acid number of 10 or less, preferably 2or less, and most preferably less than 1, and (iii) prepared by reactinga polymerized fatty acid with a diol selected from the group consistingof neopentyl glycol and 2,2,4-trimethyl-1,3-pentane diol, and

b) an organic aliphatic monoisocyanate at an isocyanate to hydroxylequivalent ratio of from 1:1 to 1:10.

The invention is also directed to isocyanate reactive compositionscontaining the release agents and to the use of the release agents in aRIM process.

It has been found that this particular combination of materials givesexcellent release from a variety of different mold surfaces. Excellentrelease occurs when the mold surface has been pre-sprayed with anexternal release agent. It has also been found that release from a baremetal mold, such as steel or aluminum, is possible without anypre-application of external mold release agent to the mold surface.Finally, the release agents herein are compatible with active hydrogencontaining mixtures which are typically used in the preparation ofreaction injection molded ("RIM") parts.

The polyesters useful herein (i) have OH numbers of from about 50 toabout 550, preferably from about 50 to about 300, and most preferablyfrom about 100 to about 200, (ii) have acid numbers of 10 or less,preferably 2 or less, and most preferably less than 1, and (iii) areprepared by reacting a polymerized fatty acid with a diol selected fromthe group consisting of neopentyl glycol and 2,2,4-trimethyl-1,3-pentanediol.

Polymerized fatty acids are known in the art. See, e.g., U.S. Pat. Nos.4,602,079, 4,680,379, 4,853,430 and 4,937,320, the disclosures of whichare herein incorporated by reference. As used herein, and as used in theart, the term "polymerized fatty acids" is intended to mean those chosenfrom the group consisting of the dimers and trimers of unsaturatedaliphatic monoacids containing from 8 to 24 carbon atoms, and mixturesthereof. Specific polymerized fatty acids useful herein are commerciallyavailable from Unichema International under the trademark "Pripol", andfrom Henkel under the trademark "Empol". Specific polymerized fattyacids include Pripol 1008, Pripol 1009, Pripol 1004, Empol 1014, Empol1009, and Empol 1010.

The polyesters used are prepared by esterifying a polymerized fatty acidwith a specific diol. The diol used is either neopentyl glycol or2,2,4-trimethyl-1,3-pentanediol.

Preparation of the fatty acid esters is most suitably carried out by thecondensation of the diol and acid at temperatures above 100° C.,preferably at 120° C. to 220° C., optionally in a vacuum, the process ofthe elimination of water being continued until the desired hydroxyl andacid numbers have been obtained. The process of esterification may, ofcourse, be catalyzed with acid or basic catalysts and the water may beeliminated by azeotropic distillation. When using neopentyl glycol, insome instances, it is desirable to add a small amount of propyleneglycol in order to help reflux the neopentyl glycol. When used, thepropylene glycol is used in an amount of from 5 to 10% by weight basedon the total weight of the neopentyl glycol. The products prepared andused according to the invention contain predominant amounts of hydroxylgroups and may contain small amounts of carboxylic acid groups.

General techniques for the preparation of the esters of the type usefulherein are generally known and are described in U.S. Pat. Nos.4,201,847, 4,254,228, and 3,925,527, the disclosures of which are hereinincorporated by reference.

Any suitable aliphatic organic monoisocyanate containing five or morecarbon atoms exclusive of the isocyanate group may be used to preparethe internal mold release agents herein. Organic monoisocyanates whichcontain more than 5 and up to twenty carbon atoms in the molecule arepreferred.

Specific isocyanates useful herein include tetradecyl isocyanate,hexadecyl isocyanate, octadecyl isocyanate, cyclohexyl isocyanate,isopentyl isocyanate, isononyl isocyanate, monoisocyanates derived fromamines which can be obtained synthetically from resinic acids or fattyacids, for example, dihydroabietyl isocyanate, oleyl or stearylisocyanate. Octadecyl isocyanate is the presently preferred isocyanate.

Reaction of the polyester with the monoisocyanate is generally carriedout by mixing the polyester with the monoisocyanate and reacting thecomponents at temperatures between 30° C. and 200° C., preferablybetween 45° C. and 110° C., optionally with stirring. Lower reactiontemperatures could also in principle be used but the length of timewhich would then be required for complete reaction of the components toobtain suitable reaction products for the process would be uneconomical.

The equivalent ratio of hydroxyl groups to isocyanate groups in thereaction of the polyester with the monoisocyanate is generallymaintained between 10:1 and 1:1.

The release agents of the present invention are eminently suitable foruse in the RIM process. As is known, in the RIM process, an isocyanate,and active hydrogen containing compounds are mixed and injected intomolds, where the reactants are allowed to react fully.

Starting polyisocyanate components suitable for use in the RIM processinclude aliphatic, cycloaliphatic, araliphatic, aromatic andheterocyclic polyisocyanates of the type described, for example, by W.Siefken in Justus Liebigs Annalen der Chemie, 562, pages 72 to 136.Specific examples of useful isocyanates include ethylene diisocyanate;1,4-tetramethylene diisocyanate; 1,6-hexamethylene diisocyanate;1,12-dodecane diisocyanate; cyclobutane-1,3-diisocyanate;cyclohexane-1,3- and -1,4-diisocyanate and mixtures of these isomers.Additional examples are 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (German Auslegeschrift 1,202,785, U.S. Pat. No. 3,401,190),2,4- and 2,6-hexahydrotolylene diisocyanate and mixtures of theseisomers. Hexahydro-1,3- and/or -1,4-phenylene diisocyanate;perhydro-2,4'- and/or -4,4'-diphenylmethane diisocyanate; 1,3- and1,4-phenylene diisocyanate; 1,4- and 2,6-tolylene diisocyanate andmixtures of these isomers are also suitable in the instant invention.Diphenylmethane-2,4- and/or -4,4'-diisocyanate;naphthylene-1,5-diisocyanate; triphenyl methane-4,4',4"-triisocyanate;polyphenyl polymethylene polyisocyanates of the type obtained bycondensing aniline with formaldehyde, followed by phosgenation anddescribed, for example, in British Patents 874,430 and 848,671 may alsobe used in the present invention; m- and p-isocyanato-phenyl-sulfonylisocyanates as described in U.S. Pat. No. 3,454,606; perchlorinated arylpolyisocyanates of the type described, for example, in GermanAuslegeschrift 1,157,601 (U.S. Pat. No. 3,277,138); polyisocyanatescontaining carbodiimide groups of the type described in German patent1,902,007 (U.S. Pat. No. 3,152,162); diisocyanates of the type describedin U.S. Pat. No. 3,492,330; and polyisocyanates containing allophanategroups of the type described, for example, in British patent 993,890, inBelgian patent 761,626 and in published Dutch Patent application7,102,524 are still further examples of suitable isocyanates.Additionally, polyisocyanates containing isocyanurate groups of the typedescribed, for example, in U.S. Pat. No. 3,001,973; in German patents1,022,789; 1,222,067 and 1,027,394 and in German Offenlegungsschriften1,929,034 and 2,004,408; polyisocyanates containing urethane groups ofthe type described, for example, in Belgian patent 752,261 or in U.S.Pat. No. 3,394,164; polyisocyanates containing acylated urea groupsaccording to German patent. 1,230,778 and polyisocyanates containingbiuret groups of the type described, for example, in German Patent1,101,394 (U.S. Pat. Nos. 3,124,605 and 3,201,372) and in British Patent889,050 are also suitable.

Polyisocyanates produced by telomerization reactions of the typedescribed, for example, in U.S. Pat. No. 3,654,106; polyisocyanatescontaining ester groups of the type described for example, in BritishPatents 965,474 and 1,072,956, in U.S. Pat. No. 3,567,763 and in GermanPatent 1,231,688; reaction products of the above-mentioned isocyanateswith acetals according to German Patent 1,072,385 and polyisocyanatescontaining polymeric fatty acid residues, according to U.S. Pat. No.3,455,883 are still further examples of suitable isocyanates.

Aromatic polyisocyanates which are liquid at the processing temperatureare preferably used. The particularly preferred starting polyisocyanatesinclude derivatives of 4,4'-diisocyanato-diphenylmethane which areliquid at room temperature, for example, liquid polyisocyanatescontaining urethane groups of the type obtainable in accordance withGerman Patent 1,618,380 (U.S. Pat. No. 3,644,457). These may be producedfor example, by reacting 1 mol of 4,4'-diisocyanatodiphenylmethane withfrom 0.05 to 0.3 mols of low molecular weight diols or triols,preferably polypropylene glycols having a molecular weight below 700.Also useful are diisocyanates based on diphenylmethane diisocyanatecontaining carbodiimide and/or uretone imine groups of the typeobtainable, for example, in accordance with German patent 1,092,007(U.S. Pat. No. 3,152,162). Mixtures of these preferred polyisocyanatescan also be used. In general, aliphatic and cycloaliphatic isocyanatesare less suitable for the purposes of the instant invention.

Also preferred are the polyphenyl-polymethylene polyisocyanates obtainedby the phosgenation of an aniline/formaldehyde condensate.

Also necessary for preparing molded products via the RIM process areisocyanate reactive components. These components may be typicallydivided into two groups, high molecular weight compounds having amolecular weight of 400 to about 10,000 and low molecular weightcompounds, i.e. chain extenders, having a molecular weight of 62 to 399.Examples of suitable high molecular weight compounds include thepolyesters, polyethers, polythioethers, polyacetals and polycarbonatescontaining at least 2, preferably 2 to 8 and most preferably 2 to 4isocyanate-reactive groups of the type known for the production ofpolyurethanes.

The high molecular weight polyethers suitable for use in accordance withthe invention are known and may be obtained, for example, bypolymerizing epoxides such as ethylene oxide, propylene oxide, butyleneoxide, tetrahydrofuran, styrene oxide or epichlorohydrin in the presenceof BF₃ or by chemically adding these epoxides, preferably ethylene oxideand propylene oxide, in admixture or successively to componentscontaining reactive hydrogen atoms such as water, alcohols or amines.Examples of alcohols and amines include the low molecular weight chainextenders set forth hereinafter, 4,4'-dihydroxy diphenyl propane,sucrose, aniline, ammonia, ethanolamine and ethylene diamine. It ispreferred to use polyethers which contain substantial amounts of primaryhydroxyl groups in terminal positions (up to 90% by weight, based on allof the terminal hydroxyl groups present in the polyether). Polyethersmodified by vinyl polymers, of the type formed, for example, bypolymerizing styrene or acrylonitrile in the presence of polyether (U.S.Pat. Nos. 3,383,351; 3,304,273; 3,523,093; and 3,110,695; and GermanPatent 1,152,536), are also suitable, as are polybutadienes containingOH groups.

In addition, polyether polyols which contain high molecular weightpolyadducts or polycondensates in finely dispersed form or in solutionmay be used. Such modified polyether polyols are obtained whenpolyaddition reactions (e.g., reactions between polyisocyanates andamino functional compounds) or polycondensation reactions (e.g., betweenformaldehyde and phenols and/or amines) are directly carried out in situin the polyether polyols.

Suitable examples of high molecular weight polyesters include thereaction products of polyhydric, preferably dihydric alcohols(optionally in the presence of trihydric alcohols), with polyvalent,preferably divalent, carboxylic acids. Instead of using the freecarboxylic acids, it is also possible to use the correspondingpolycarboxylic acid anhydrides or corresponding polycarboxylic acidesters of lower alcohols or mixtures thereof for producing thepolyesters. The polycarboxylic acids may be aliphatic, cycloaliphatic,aromatic, and/or heterocyclic and may be unsaturated or substituted, forexample, by halogen atoms. The polycarboxylic acids and polyols used toprepare the polyesters are known and described for example in U.S. Pat.Nos. 4,098,731 and 3,726,952, herein incorporated by reference in theirentirety. Suitable polythioethers, polyacetals, polycarbonates and otherpolyhydroxyl compounds are also disclosed in the above-identified U.S.Patents. Finally, representatives of the many and varied compounds whichmay be used in accordance with the invention may be found for example inHigh Polymers, Volume XVI, "Polyurethanes, Chemistry and Technology," bySaunders-Frisch, Interscience Publishers, New York, London, Vol. I,1962, pages 32-42 and 44-54, and Volume II, 1964, pages 5-6 and 198-199;and in Kunststoff-Handbuch, Vol. VII, Vieweg-Hochtlen, Carl HanserVerlag, Munich, 1966, pages 45-71.

Suitable aminopolyethers which may be used in accordance with thepresent invention as high molecular weight compounds (the molecularweight is always the average molecular weight which may be calculatedfrom the functionality and the content of isocyanate-reactive groups)are those wherein at least about 30 and preferably about 60 to 100equivalent % of the isocyanate-reactive groups are primary and/orsecondary (preferably primary) aromatically or aliphatically (preferablyaromatically) bound amino groups and the remainder are primary and/orsecondary aliphatically bound hydroxyl groups.

In these compounds, the terminal residues carrying the amino groups mayalso be attached to the polyether chain by urethane or ester groups.These "aminopolyethers" are prepared by methods known per se. Forexample, polyhydroxypolyethers such as polypropylene glycol ethers maybe aminated by reaction with ammonia in the presence of Raney nickel andhydrogen (Belgian Patent 634,741). U.S. Pat. No. 3,654,370 describes theproduction of polyoxyalkylene polyamines by reaction of thecorresponding polyol with ammonia and hydrogen in the presence of anickel, copper, chromium catalyst. German Patent 1,193,671 describes theproduction of polyethers containing terminal amino groups byhydrogenation of cyanoethylated polyoxypropylene ethers. Other methodsfor the production of polyoxyalkylene (polyether) amines are describedin U.S. Pat. Nos. 3,155,728 and 3,236,895 and French Patent 1,551,605.The production of polyethers containing terminal secondary amino groupsis described, for example, in French Patent 1,466,708.

Polyhydroxypolyethers of relatively high molecular weight may beconverted into the corresponding anthranilic acid esters by reactionwith isatoic acid anhydride, as described, for example, in GermanOffenlegungsschriften 2,019,432 and 2,619,840 and in U.S. Pat. Nos.3,808,250, 3,975,428 and 4,016,143. Polyethers containing terminalaromatic amino groups are formed in this way.

According to German Offenlegungsschrift 2,546,536 and U.S. Pat. No.3,865,791, relatively high molecular weight compounds containingterminal amino groups are obtained by reaction of NCO prepolymers basedon polyhydroxypolyethers with enamines, aldimines or ketiminescontaining hydroxyl groups and subsequent hydrolysis.

It is preferred to use amino polyethers obtained by hydrolysis ofcompounds containing terminal isocyanate groups, for example inaccordance with German Offenlegungsschrift 2,948,419 or U.S. Pat. No.4,515,923, which is herein incorporated by reference. In this process,polyethers most preferably containing 2 to 4 hydroxyl groups are reactedwith polyisocyanates to form NCO prepolymers and, in a second step, theisocyanate groups are converted by hydrolysis into amino groups.

Also useful are amino compounds prepared by reacting the correspondingpolyol with a halogenated nitrobenzene compound such as o- orp-nitrochlorobenzene, followed by the reduction of the nitro group(s) tothe amine as described in U.S. application Ser. No. 183,556, filed onApr. 19, 1988, and in published European application 0268849, publishedJun. 1, 1988.

The "aminopolyethers" used in accordance with the invention are oftenmixtures of the compounds mentioned by way of example and (on astatistical average) most preferably contain 2 to 4 terminalisocyanate-reactive groups. In the process according to the invention,the "aminopolyethers" may be used in admixture withpolyhydroxypolyethers free from amino groups.

In accordance with the present invention, the high molecular weightcompounds can be used in admixture with up to about 95% by weight basedon the total quantity of active hydrogen containing compounds, of lowmolecular weight chain extenders. Examples of suitable hydroxylgroup-containing chain extenders include ethylene glycol, 1,2- and1,3-propane diol, 1,3- and 1,4- and 2,3-butane diol, 1,6-hexane diol,1,10-decane diol, diethylene glycol, triethylene glycol, tetraethyleneglycol, dipropylene glycol, tripropylene glycol, glycerol andtrimethylol propane.

Other suitable chain extenders include aromatic polyamines, preferablydiamines, having molecular weights of less than 400, especially thesterically hindered aromatic polyamines, preferably diamines, havingmolecular weights of less than 400, especially the sterically hinderedaromatic diamines which contain at least one linear or branched alkylsubstituent in the ortho-position to the first amino group and at leastone, preferably two linear or branched alkyl substituents containingfrom 1 to 4, preferably 1 to 3, carbon atoms in the ortho-position to asecond amino group. These aromatic diamines include1-methyl-3,5-diethyl2,4-diamino benzene,1-methyl-3,5-diethyl-2,6-diamino benzene, 1,3,5-trimethyl-2,4-diaminobenzene, 1,3,5-triethyl-2,4-diamino benzene,3,5,3',5'-tetraethyl-4,4'-diamino diphenylmethane,3,5,3',5'-tetraisopropyl-4,4'-diamino diphenylmethane,3,5-diethyl-3',5'-diisopropyl-4,4'-diamino diphenylmethane,3,5-diethyl-5,5'-diisopropyl-4,4'-diamino diphenylmethane,1-methyl-2,6-diamino-3-isopropylbenzene and mixtures of the abovediamines. Most preferred are mixtures of1-methyl-3,5-diethyl-2,4-diamino benzene and1-methyl-3,5-diethyl-2,6-diamino benzene in a weight ratio between about50:50 to 85:15, preferably about 65:35 to 80:20.

In addition, aromatic polyamines may be used in admixture with thesterically hindered chain extenders and include, for example, 2,4- and2,6-diamino toluene, 2,4'- and/or 4,4'-diaminodiphenylmethane, 1,2- and1,4-phenylene diamine, naphthalene-1,5-diamine andtriphenylmethane-4,4',4"-triamine. The difunctional and polyfunctionalaromatic amine compounds may also exclusively or partly containsecondary amino groups such as 4,4'-di-(methylamino)-diphenylmethane or1-methyl-2-methylamino-4-amino-benzene. Liquid mixtures of polyphenylpolymethylene-polyamines, of the type obtained by condensing anilinewith formaldehyde, are also suitable. Generally, the nonstericallyhindered aromatic diamines and polyamines are too reactive to providesufficient processing time in a RIM system. Accordingly, these diaminesand polyamines should generally be used in combination with one or moreof the previously mentioned sterically hindered diamines or hydroxylgroup-containing chain extenders.

Other additives which may be used in the RIM process according to thepresent invention include catalysts, especially tin(II) salts ofcarboxylic acids, dialkyl tin salts of carboxylic acids, dialkyl tinmercaptides, dialkyl tin dithioesters and tertiary amines. Preferredamong these catalysts are dibutyl tin dilaurate and1,4-diazabicyclo-(2,2,2)-octane (triethylene diamine), especiallymixtures of these catalysts. The catalysts are generally used in amountsof about 0.01 to 10%, preferably about 0.05 to 2%, based on the weightof the isocyanate reactive component.

It is also possible to use surface-active additives such as emulsifiersand foam stabilizers. Examples include N-stearyl-N',N'-bis-hydroxyethylurea, oleyl polyoxyethylene amide, stearyl diethanol amide, isostearyldiethanolamide, polyoxyethylene glycol monoleate, apentaerythritol/adipic acid/oleic acid ester, a hydroxy ethyl imidazolederivative of oleic acid, N-stearyl propylene diamine and the sodiumsalts of castor oil sulfonates or of fatty acids. Alkali metal orammonium salts of sulfonic acid such as dodecyl benzene sulfonic acid ordinaphthyl methane sulfonic acid and also fatty acids may also be usedas surface-active additives.

Suitable foam stabilizers include water-soluble polyether siloxanes. Thestructure of these compounds is generally such that a copolymer ofethylene oxide and propylene oxide is attached to a polydimethylsiloxane radical. Such foam stabilizers are described in U.S. Pat. No.2,764,565. In addition to the catalysts and surface-active agents, otheradditives which may be used in the molding compositions of the presentinvention include known blowing agents, cell regulators, flame retardingagents, plasticizers, dyes, fillers and reinforcing agents such as glassin the form of fibers or flakes or carbon fibers.

The molded products of the present invention are prepared by reactingthe components in a closed mold. The compositions according to thepresent invention may be molded using conventional processing techniquesat isocyanate indexes ranging from as low as 90 to as high as 400(preferably from 95 to 115) and are especially suited for processing bythe RIM process. In general, two separate streams are intimately mixedand subsequently injected into a suitable mold, although it is possibleto use more than two streams. The first stream contains thepolyisocyanate component, while the second stream contains theisocyanate reactive components and any other additive which is to beincluded. According to the present invention, the internal release agentis added to the isocyanate reactive components, generally in an amountof from 2 to 20% by weight, and preferably from 3 to 10% by weight,based on the total weight of the isocyanate reactive components.

The invention is further illustrated but is not intended to be limitedby the following examples in which all parts and percentages are byweight unless otherwise specified.

EXAMPLES

POLYESTER A: A twelve liter flask was charged with 1558 parts ofneopentyl glycol. 156 parts of propylene glycol (approximately 10% byWeight of the total neopentyl glycol) was added to help reflux theneopentyl glycol that would otherwise be lost due to sublimation.Nitrogen was bubbled through the flask and the temperature of the flaskwas raised to 160° C. 4322 parts of dimer acid (Pripol 1009, availablefrom Unichema) were slowly added with stirring and the temperature wasraised to 220° C. at the completion of the addition. Water was collectedin the receiving flask. After the atmospheric cycle, vacuum was slowlyapplied to the system and more water was distilled over (a total of 270parts of water were collected). Full vacuum was then applied and 156parts of propylene glycol were distilled over. The polyester gave bytitration, the following: acid number--about 0.8, and OH number--about135.

IMR 1: A twelve liter flask was charged with 4123 parts of octadecylisocyanate and 5610 parts of POLYESTER A. The temperature of the flaskwas raised to 80° C. and 0.5 parts of dibutyltin dilaurate were added.The temperature was then raised to 100° C. and the reaction sequence wasmonitored by IR. The final product showed a complete disappearance ofboth the NCO and the OH peaks by IR characterization.

POLYESTER B: A twelve liter flask was charged with 2188 parts of2,2,4-trimethyl-1,3-pentane diol. Nitrogen was bubbled through the flaskand the temperature of the flask was raised to 160° C. 4322 parts ofdimer acid (Pripol 1009, available from Unichema) were slowly added withstirring and the temperature was raised to 220° C. at the completion ofthe addition. Water was collected in the receiving flask. After theatmospheric cycle, vacuum was slowly applied to the system and Morewater was distilled over (a total of 268 parts of water were collected).The polyester gave by titration, the following: acid number--about 0.9,and OH number--about 134.

IMR 2: A twelve liter flask was charged with 4123 parts of octadecylisocyanate and 5610 parts of POLYESTER B. The temperature of the flaskwas raised to 80° C. and 0.5 parts of dibutyltin dilaurate were added.The temperature was then raised to 100° C. and the reaction sequence wasmonitored by IR. The final product showed a complete disappearance ofboth the NCO and the OH peaks by IR characterization.

POLYESTER C (comparative): A twelve liter flask was charged with 3671parts of neopentyl glycol. 360 parts of propylene glycol (approximately10% by weight of the total neopentyl glycol) was added to help refluxthe neopentyl glycol that would otherwise be lost due to sublimation.Nitrogen was bubbled through the flask and the temperature of the flaskwas raised to 160° C. 2575 parts of adipic acid were slowly added withstirring and the temperature was raised to 220° C. at the completion ofthe addition. Water was collected in the receiving flask. After theatmospheric cycle, vacuum was slowly applied to the system and morewater was distilled over (a total of 636 parts of water were collected).Full vacuum was then applied and 360 parts of propylene glycol weredistilled over. The polyester gave by titration, the following: acidnumber--about 0.7, and OH number--about 135.

IMR 3 (comparative): A twelve liter flask was charged with 4123 parts ofoctadecyl isocyanate and 5610 parts of POLYESTER C. The temperature ofthe flask was raised to 80° C. and 0.5 parts of dibutyltin dilauratewere added. The temperature was then raised to 100° C. and the reactionsequence was monitored by IR. The final product showed a completedisappearance of both the NCO and the OH peaks by IR characterization.

RIM Examples

In the examples which follow, the following materials were used:

POLYAMINE A: an amine terminated polyether having an amine number ofabout 30 and prepared hydrolyzing an isocyanate terminated prepolymerwhich had been prepared by reacting toluene diisocyanate with a 4800molecular weight glycerin/propylene oxide/ethylene oxide polyether(PO:EO ratio was about 5:1; the polyether had an OH number of 35 and hadprimary OH termination);

POLYAMINE B: a 1:1 mixture of a 3000 molecular weight propylene oxidetriamine and a 2000 molecular weight propylene oxide diamine, bothavailable from Texaco;

DETDA: an 80:20 mixture of 1-methyl-3,5-diethyl-2,4- and -2,6-phenylenediamine;

POLYOL A: a reaction product of ethylene diamine and propylene oxidehaving an OH number of about 630;

L-5304: a silicone surfactant available from Union Carbide;

ISO: an isocyanate having an NCO content of about 22% and prepared by i)reacting 252 parts of 4,4'-methylenebis(phenyl isocyanate), 27 parts ofa carbodiimide-group modified 4,4'-methylenebis(phenyl isocyanate)having an NCO content of about 29%, and 169 parts of a 2000 molecularweight diol (prepared by reacting adipic acid, ethylene glycol and1,4-butane diol), and ii) blending 4800 parts of the resultant productwith 1200 parts of a polymethylenepoly(phenyl isocyanate) having an NCOcontent of about 33%, with a 19% by weight 2,4'-isomer content and anisocyanate functionality of about 2.4.

RIM plaques were prepared using a laboratory piston metering unit andclamping unit. The metering unit was a two component instrument having amaximum metering capacity of 0.6 liters. A rectangular mold, 300 mm×200mm×4 mm, was used to mold the samples. The mold was first stripped witha mold cleaner (N-methyl pyrrolidinone), then soaped (with Chemtrend2006, available from Chemtrend) and then buffed twice. An aluminumtransducer plate (2.2 inch radius) was connected to a force transducermounted in the lid of the mold. The plate was soaked in DMF for an hour,polished with fine steel wool, rinsed with water and then rinsed withacetone. A RIM shot was then made, and at the demold time of 45 seconds,the lid of the mold was slowly opened. The maximum force required topull the transducer plate from the molded plaque is the release force.The lower the number, the easier the release.

The following molding conditions were used:

Mold Temperature: 65° C.

Component B temp: 45° C.

Component A temp: 45° C.

Two different formulations were used. 3 parts by weight of internalrelease agent ("IMR") were tested in the following formulation:

    ______________________________________                                        Component B:                                                                  POLYAMIDE A:     33.6                                                         POLYAMINE B:     33.6                                                         DETDA:           26.0                                                         L-5304:          0.8                                                          IMR:             3.0                                                          Component A:                                                                  ISO:             77.3                                                         ______________________________________                                    

4 parts by weight of internal release agent ("IMR") were tested in thefollowing formulation:

    ______________________________________                                        Component B:                                                                  POLYAMIDE A:     33.1                                                         POLYAMINE B:     33.1                                                         DETDA:           26.0                                                         L-5304:          0.8                                                          IMR:             4.0                                                          Component A:                                                                  ISO:             77.1                                                         ______________________________________                                    

The results were as follows, with the release force reported in poundsper square inch:

    ______________________________________                                        Amount                       EXAMPLE 4                                        of                           FROM                                             IMR      IMR 1       IMR 2   '527 PAT                                         ______________________________________                                        3 parts  18.3        16      24.2                                             4 parts  14.9        12      26.3                                             ______________________________________                                    

Neither IMR 3 nor the release agent of Example 4 of the '527 patent(i.e., U.S. Pat. No. 3,925,527) were compatible with the B-side and hadto be blended with the isocyanate. The system using IMR 3 would notrelease.

Although the invention has been described in detail in the foregoing forthe purpose of illustration, it is to be understood that such detail issolely for that purpose and that variations can be made therein by thoseskilled in the art without departing from the spirit and scope of theinvention except as it may be limited by the claims.

What is claimed is:
 1. An internal release composition comprising thereaction product ofa) a polyester (i) having an OH number of from about50 to about 550, (ii) an acid number of 4 or less, and (iii) prepared byreacting a polymerized fatty acid with a diol selected from the groupconsisting of neopentyl glycol and 2,2,4-trimethyl-1,3-pentane diol, andb) an aliphatic monoisocyanate containing five or more carbon atomsexclusive of the isocyanate group, at an isocyanate to hydroxylequivalent ratio of from 1:1 to 1:10.
 2. The composition of claim 1,wherein said OH number is from 50 to 300 and said acid number is 2 orless.
 3. The composition of claim 2, wherein said OH number is from 100to 200 and said acid number is less than
 1. 4. An isocyanate reactivecomposition comprising:i) at least one isocyanate reactive compoundhaving a molecular weight of from 400 to 10,000 and containing at leasttwo isocyanate reactive groups, and ii) from about 2 to about 20% byweight based upon the weight of all the isocyanate reactive compounds ofthe reaction product ofa) a polyester (i) having an OH number of fromabout 50 to about 550, (ii) an acid number of 4 or less, and (iii)prepared by reacting a polymerized fatty acid with a diol selected fromthe group consisting of neopentyl glycol and 2,2,4-trimethyl-1,3-pentanediol, and b) an aliphatic monoisocyanate containing five or more carbonatoms exclusive of the isocyanate group, at an isocyanate to hydroxylequivalent ratio of from 1:1 to 1:10.
 5. The composition of claim 4further containing at least one isocyanate reactive compound having amolecular weight of from 62 to 399 and containing at least twoisocyanate reactive groups.
 6. The composition of claim 5, wherein saidreaction product is present in an amount of from 3 to 10% by weight. 7.In a process for the preparation of a molded polyurethane and/orpolyurea elastomer by injecting a mixture of an isocyanate and anisocyanate reactive composition into a closed mold via the RIMtechnique, the improvement wherein said mixture contains from about 2 toabout 20% by weight based upon the weight of all the isocyanate reactivecompounds of the reaction product ofa) a polyester (i) having an OHnumber of from about 50 to about 550, (ii) an acid number of 4 or less,and (iii) prepared by reacting a polymerized fatty acid with a diolselected from the group consisting of neopentyl glycol and2,2,4-trimethyl-1,3-pentane diol, and b) an aliphatic monoisocyanatecontaining five or more carbon atoms exclusive of the isocyanate group,at an isocyanate to hydroxyl equivalent ratio of from 1:1 to 1:10.